To continue to collect and to study clinicopathologic materials from the Macula Clinic. The natural history of macular dysfunctions of various types will be documented. Patients will be urged to pledge their eyes for pathologic examination whenever appropriate. Retinitis proliferans in retrolental fibroplasia in kittens will be our intense subject of study. The patterns of leakage from new vessels and the development and the regression of these vessels will be examined. The effect of photocoagulation on the new vessels will be observed. We shall continue to examine the possible relationship of prostaglandin to macular edema. The histopathologic study of occlusion of central arteries and veins will be continued. We shall examine the effect of trauma in the production of Berlin's edema and the possible leakage from the retinal and choroidal vasculature in the eye of rhesus monkey by horseradish peroxidase tracer technique.